The frequency of an electronic oscillator is generally determined by its inductance and capacitance. In some oscillators, capacitor arrays comprising a plurality of unit capacitances are provided. Depending on a control input of the oscillator, these capacitances of the capacitance array are selectively activated and deactivated to change the frequency of a signal generated by the oscillator.
For example, in so-called digital controlled oscillator using thermometer decoding, a capacitance array comprises a plurality of capacitances with nominally equal capacitance values. A number of capacitances corresponding to a number represented by the digital control word is activated. Such a control scheme leads to a non-linear dependency of the frequency from the control word.